The disclosed technology relates generally to transmitting and receiving messages over a wireless communications network, and more particularly to distributing encoded data across a plurality of redundancy versions for transmission and receipt over the wireless communications network.
In accordance with various wireless communications standards, each base station and mobile station employs a rate matcher. The rate matcher determines which of the bits in an encoded message to send in a current transmission block. For reasons related to data integrity, and because the encoded message may be substantially larger than the amount of data that can be transmitted in a single transmission block, a transmitting station (e.g., a base station or a mobile station) may perform multiple transmissions based on the same encoded message before the receiving station (e.g., a mobile station or a base station) can recover the message. The rate matcher, therefore, determines which set of bits to select for each transmission block.
There are several known rate matching algorithms that are employed by cellular communications systems today. These algorithms have several weaknesses. One weakness is the high percentage of bits in the encoded message that are not selected for transmission within a reasonable number of transmissions. Another weakness is the drastic decrease in decoding performance if the receiving station is not able to interpret the header in one of the transmissions. Accordingly, it would be desirable to provide a rate matcher that is capable of a high decoding performance in different operating scenarios.